This invention broadly relates to helicopters and similar aircraft which carry cargo externally. In a specific aspect the invention pertains to helicopters deploying cargo retrieving lines.
Over the past two decades the helicopter has become significantly important in both its military and commercial applications. Generally, one main advantage that has enhanced the utility of this craft has been its ability to lift significant loads to extraordinary heights, and does so with the use of various hoisting means that can initially raise the load from the ground, before the helicopter undertakes some movement to the desired location for reimplacement of its carried load.
Since cargo retrieving, including carrying, lines cannot dangle dangerously when not attached to a load, winch-type hoists such as that shown in U.S. Pat. No. 4,244,561 are employed. While hoists have become significantly important in both military and commercial application, there are certain deficienies in the conventional mechanisms that render the usage of structured hoists somewhat deficient, and in many instances, even hazardous in certain applications. For example, most of the hoisting means available in the prior art include a winch having a single cable pay-out. The cable release is achieved by means of a supporting drum, which automatically translates a slight shifting momentum to the load itself, in many instances even before it is raised off the ground or other supporting structure. As a result, there is a tendency for the load being lifted by the helicopter to sway upon its release of contact with the ground. This can be extremely hazardous to surrounding workers or property.
Even more important, there are some operations which require rapid pick-up of cargo or personnel within time constraints impossible for winch mechanisms to meet. If a clutch were released, permitting cargo retrieving line free fall, the cargo nook would necessarily have to be so heavy as to unwind the line within the winch. Such heavy cargo hooks are not practical for use in rapidly executed operations. In addition, where several rapidly deployed lines are desired, a winch mechanism will not suffice. The invention herein has an object the improvement of cargo retrieving line dispensing helicopters to permit rapid deployment of several cargo lines in extremely short cargo retrieving time spans.